I was going to mention that, but I couldn't quite remember whether it was true or just a delusion. There were two types of formats, the simple one really didn't do much at all. The quick format just deleted the address table that showed where each sector began and what was in it. The data on the disk was untouched, and could be easily recovered. I think the full-format was more severe in that it attempted to wipe the disk. I'm not sure how effective that was, though.